An active optical cable is an optical fiber cable that is terminated on one or both ends with a plug that contains an optical transceiver module. The plug has a housing that is typically configured to be received within an opening formed in a cage. Mechanical coupling features on the plug housing form a latch that interlocks with mechanical coupling features on the cage to secure the plug housing to the cage. When the plug housing is fully inserted into the cage, the latch of the plug housing engages one or more of the mechanical coupling features of the cage to lock the plug housing inside of the cage. The latch of the plug housing is typically operable by a user to be placed in a delatching position that decouples the plug housing from the cage to enable the user to remove the plug housing from the cage.
FIG. 1 illustrates a top perspective view of a known Quad Small Form-Factor Pluggable (QSFP) active optical cable 2 currently used in the optical communications industry. An optical fiber cable 3 of the QSFP active optical cable 2 includes a plurality of transmit optical fibers (not shown for purposes of clarity) and a plurality of receive optical fibers (not shown for purposes of clarity). The end 3a of the cable 3 is terminated with a plug 4. The plug 4 has a housing 5 in which the aforementioned optical transceiver module (not shown for purposes of clarity) is housed. The plug housing 5 includes a first housing portion 5a and a second housing portion 5b, which are connected together by fastening elements (not shown for purposes of clarity). The first and second portions 5a and 5b of the plug housing 5 are typically made of cast aluminum, cast zinc, or a cast zinc alloy.
A delatch device 6 of the plug 4 allows the plug housing 5 to be delatched from a cage (not shown for purposes of clarity) to enable the plug housing 5 to be removed from the cage. A pull tab 7 is connected on its proximal end 7a to the delatch device 6. When a user pulls on the distal end 7b of the pull tab 7 in the direction indicated by arrow 8, slider portions 6a and 6b of the delatch device 6 move to a limited extent in the direction indicated by arrow 8 (only slider portion 6a can be seen in FIG. 1). This movement of the slider portions 6a and 6b causes outwardly curved ends 6a′ and 6b′ of the slider portions 6a and 6b, respectively, to press against respective catch features on the cage (not shown for purposes of clarity) to allow the plug housing 5 to be retracted from the cage.
The majority of active optical cables currently used in the optical communications industry have configurations that are similar to that of the QSFP active optical cable 2 shown in FIG. 1, although other types of active optical cables of other form factors are also used in the industry. In QSFP active optical cables of the type shown in FIG. 1, the optical transceiver module housed in the plug housing 5 typically includes parallel arrays of vertical cavity surface emitting lasers (VCSELs), parallel arrays of photodiodes, and parallel laser driver and receiver integrated circuit (IC) chips. These parallel components are mounted on an upper surface of a plug printed circuit board (PCB) 9. The parallel components, particularly the VCSEL arrays, are relatively expensive due in large part to the fact that a high degree of uniformity is required among the VCSELs. In addition, the parallel components used in these modules are manufactured in relatively low volumes, and thus generally have higher costs associated with them.
A need exists for a CIO optical transceiver module for use in an active optical cable that can be manufactured at relatively low costs with high quality and that is particularly well suited for consumer applications.